Case statement in stored procedure - Unknown System Variable

Question

I'm trying to use a case statement to update a column based on the value of another column. My table called 'rma' in MySQL is as follows:

ID    |    rma_number    |     serial_number     |    ref_status_id
1     |       9898       |         123456        |          19
2     |       7869       |         098768        |           3

Here is my stored procedure:

CREATE DEFINER=`admin`@`localhost` PROCEDURE `delete_update_rma`(in selectedID int, in selectedRMAID int)
begin

declare rmaStatus int(5);

select ref_status_id into rmaStatus
from rma
where id = selectedRMAID;

case rmaStatus
when 19 then
set ref_status_id = 0;

end case;

delete from dropbox where id = selectedID;

end

When I try to save to create the procedure I receive the error #1193 - Unknown system variable 'ref_status_id'.

Can anybody help me identify what may be wrong with my stored procedure?

Answer 1

Try this:

CREATE DEFINER=`admin`@`localhost` PROCEDURE `delete_update_rma`(IN selectedID INT, IN selectedRMAID INT)
BEGIN

UPDATE rma
SET ref_status_id = 
  CASE ref_status_id
    WHEN 19 THEN 0 
    WHEN 3 THEN 2
    ELSE ref_status_id
  END
WHERE id = selectedRMAID;

DELETE FROM dropbox WHERE id = selectedID;

END

Check the SQL FIDDLE DEMO

OUTPUT

| ID | RMA_NUMBER | SERIAL_NUMBER | REF_STATUS_ID |
|----|------------|---------------|---------------|
|  1 |      12345 |         67898 |             0 |
|  2 |      45645 |         89056 |             2 |